I am seeking information or flow diagrams for the heater/cooling system for a4 1.8t, the common problem of heater not working until the revs have been increased. All leaks have been repaired and water pump has been replaced,it has been bled by every method I could come up with .Bleeding it properl has helped but the problem still exists. That is the heater does not function well at low revs. There just seems to be very poor flow at low revs.:thumbsup:
audi a4 b6 1.8t cooling system /heater
- Thread starter johndoh1966
- Start date
I had this problem and it was the head gasket. Did you have any problems bleeding it? (great big bubbles of air coming out of the expansion tank), if not you're probably luckier than me, hope it's just a leak you've not found yet.
Just a thought, does the car heat up properly with the needle sitting mid position on the gauge and staying there?
I'll try and send you a copy of the system schematic from the manual.
I'll try and send you a copy of the system schematic from the manual.
mine would blow cold air even on perfect running temp on the gauge, unless I revved it past 3k and held it, then it would blow hot. The cracked coolant flange was confirmed and it leaked whenever heat was selected as thats the heater matrix input. We saw it with a mirror, ******* out when it was put to hot air selection inside the car. Its behind the head, under the black PCV valve.
Cheap, but hard to get to, and has the exact same symptoms as you.
Cheap, but hard to get to, and has the exact same symptoms as you.
